A ubiquitous problem of growing old is difficulty seeing at night and under low illumination. Poor vision under reduced light levels in the elderly hinders their performance of daily activities, and has been linked to the occurrence of motor vehicle collisions and falls, which result in injury and elevated mortality risk. Even for those older adults who are free of significant eye disease there can be scotopic dysfunction, suggesting that these impairments are due to a biological aging of the visual system. Optical changes in the aged eye cannot account for the severity of night/low luminance vision problems, suggesting that they have a neural origin. Older adults with early age-related macular degeneration (AMD) exhibit similar night/low luminance vision problems, but theirs are typically more severe. Our long-term goal is to identify the causes of scoptic deficits in older adults and in those with early AMD so that treatment interventions to minimize or reverse these deficits can be developed thus enhancing older adults' quality of life. Studies will focus on retinal mechanisms that may underlie these impairments. The specific aims of this research plan are: (1) to identify mechanisms of scotopic sensitivity impairment and dark adaptation delays in aging and early AMD using flash electroretinography and dark adaptometry; (2) to develop a questionnaire instrument for measuring health-related quality of life that is targeted at nighttime/low luminance vision problems; and (3) to evaluate the impact of vitamin A in reversing or minimizing scotopic sensitivity and delays in dark adaptation and in enhancing vision-targeted health-related quality of life in aging and early AMD.